Main difference at CPU level is support for storage of PKI certificates inside a special memory area in CPU, protecting them from unapproved extraction and 'cold memory boot' attacks. Also, all vPro CPUs are compatible with Trusted Execution, special mechanism by which CPU checks the BIOS/EFI/OS boot loader configuration against defined policy, effectively blocking PC/server boot at early stages in case of unwanted changes of environment (Biruses, boot loader level rootkits, third-party boot managers, attempts of boot from removable media and so on). There is no difference in performance.
